1. Field of the Invention
The present invention relates to a program guide data collection and delivery system for providing electronic program guide data (hereinafter referred to just as "EPG data") which is the data concerning the programs being broadcast from a plurality of broadcasting stations to the program guide viewers of their respective stations, and also relates to a program guide data collection and delivery device that performs transmission and reception of the EPG data to and from these broadcasting stations.
2. Description of the Related Art
FIG. 13 is a schematic diagram showing a conventional program guide data transmitting device as disclosed in Japanese Patent Application Laid-Open No. 8-289267. In the figure, reference numeral 701 denotes a switcher that selects signals of predetermined plural numbers of broadcasting channels among image signals and audio signals provided in the digital form received from a plurality of broadcasting stations, numeral 702 denotes a promotion channel generating device, which transforms the signals of a predetermined limited number of channels among those of a plurality of channels input to this switcher 701 into a sole signal to be displayed on one single monitor screen. Reference numerals 703a, 703b and 703c each denotes an encoder for coding the image signals and audio signals fed from the switcher 701 by use of MPEG method (Moving Picture Expert Group method), numeral 709 denotes an EPG data generating device for generating EPG data, numeral 708 denotes a program transmission control device for outputting control signals for controlling the switcher 701 and the EPG data generating device 709 and so on, numerals 704a, 704b, 704c and 704d each denotes a multiplexing device (abbreviated to "MUX" in the figure") for respectively multiplexing the signals input from the promotion channel generating device 702, encoders 703a to 703c and from the EPG data generating device 709, and outputting thereafter these multiplexed signals. Further, reference numerals 705a, 705b, 705c and 705d each denotes a digital converter circuit that converts the multiplexed signals fed from each of the multiplexing devices 704a through 704d into digital signals, numeral 706 denotes a combiner circuit that combines the signals fed from the digital converter circuits 705a through 705d, and numeral 707 denotes a satellite-transmission antenna for transmitting the signals fed from the combiner circuit 706 to a corresponding satellite.
The operation of the above conventional program guide data transmitting device is as follows.
In FIG. 13, the EPG data generating device 709 generates EPG data consisting of bit map data such as icons, promotion logos, categories and so on which are to be transmitted under control of the program transmission control device 708, and outputs the thus generated EPG data to the promotion channel generating device 702 and also to the multiplexing devices 704a through 704d. The promotion channel generating device 702 superimposes the bit map data fed from the EPG data generating device 709 on the image signals for a small screen each input through the switcher 701. The multiplexing devices 704a through 704d multiplex the image signals and audio signals fed thereto from the promotion channel generating circuit 702 and the encoders 703a through 703d. The digital converter circuits 705a through 705d convert the input signals to digital signals by a predetermined converting method, and output the converted signals to the combiner circuit 706. The combiner circuit 706 combines the signals output from the digital converter circuits 705a through 705d, and transmits the thus composite signal to the satellite by way of an antenna 707.
However, as explained above, since the conventional program guide data transmitting device is provided as an individual equipment in each of the broadcasting stations within a program guide data collection and delivery system, and is not considered in relation to other broadcasting stations, in a case that there are already many broadcasting stations within the system, each of the stations is not capable of providing the latest EPG data of other stations for the program guide viewers of its own station.
Further, in a case that there is a modification of EPG data in each broadcasting station, the modified EPG data can be directly broadcast to all other stations in order that each broadcasting station can provide other stations with the latest EPG data of itself. However, in this case, if the modification of EGP data frequently occurs in each broadcasting station, the frequency of inter-access among the plurality of broadcasting stations is thereby made higher, and in addition to this, each time a broadcasting station is newly founded, the already existing plurality of stations have to change their respective system configurations.